You can manually add the RabbitMQ repository as described in the website.
This script will include the GPG keys and both the RabbitMQ repository and the Earlang repository.
#!/bin/sh
sudo apt-get install curl gnupg debian-keyring debian-archive-keyring apt-transport-https -y
## Team RabbitMQ's main signing key
sudo apt-key adv --keyserver "hkps://keys.openpgp.org" --recv-keys "0x0A9AF2115F4687BD29803A206B73A36E6026DFCA"
## Launchpad PPA that provides modern Erlang releases
sudo apt-key adv --keyserver "keyserver.ubuntu.com" --recv-keys "F77F1EDA57EBB1CC"
## PackageCloud RabbitMQ repository
sudo apt-key adv --keyserver "keyserver.ubuntu.com" --recv-keys "F6609E60DC62814E"
## Add apt repositories maintained by Team RabbitMQ
sudo tee /etc/apt/sources.list.d/rabbitmq.list <<EOF
## Provides modern Erlang/OTP releases
##
## "bionic" as distribution name should work for any reasonably recent Ubuntu or Debian release.
## See the release to distribution mapping table in RabbitMQ doc guides to learn more.
deb http://ppa.launchpad.net/rabbitmq/rabbitmq-erlang/ubuntu bionic main
deb-src http://ppa.launchpad.net/rabbitmq/rabbitmq-erlang/ubuntu bionic main
## Provides RabbitMQ
##
## "bionic" as distribution name should work for any reasonably recent Ubuntu or Debian release.
## See the release to distribution mapping table in RabbitMQ doc guides to learn more.
deb https://packagecloud.io/rabbitmq/rabbitmq-server/ubuntu/ bionic main
deb-src https://packagecloud.io/rabbitmq/rabbitmq-server/ubuntu/ bionic main
EOF
After that, don't forget to remove the old and defective entry from the /etc/apt/sources.list
, or your apt update will fail.